用链表编写学生管理系统（涵盖文件的输入输出）

学过链表的大家都知道，它是一种动态的数据结构，但是它理解起来是比较困难的，但是用链表存储数据是非常好用的，可以使我们的程序更加具有健壮性。为了初学者理解单项链表更加快，今天就用链表和文件操作写了一控制台的学生管理系统，希望可以帮助大家更好的理解链表。

程序实现的功能：





源代码如下

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
void AppendNode(long long studentID, char studentName[10], char studentSex[4], int score[4]);//添加数据
void DisplayNode(struct link *head);//显示数据
void InsertNode(long long studentID, char studentName[10], char studentSex[4], int score[4]);//插入一条数据；按总分的从大到小排序
void InsertNodeNumber(long long studentID, char studentName[10], char studentSex[4], int score[4]);//按学号的从小到大排序
void NumberSorting(int flag);//按从大到小对数据进行排序；1、对总分进行排序，2、对学号进行排序
void DeleteNodeID();//输入学号删除
void DeleteNodeName();//输入学号删除
void DeleteMemory(struct link *head);//删除聊表所占用的内存；
void Save();//保存数据
void Open();//打开数据
void FindID();//按学号查找学生
void FindName();//按姓名查找学生;
void Menu();
typedef struct student
{
long long studentID;
char studentName[10];
char studentSex[4];
int score[4];
}STU;
struct link
{
STU student;
struct link *next;
};
struct link *head = NULL;//保存输入的学生信息数据
struct link *head1 = NULL;//保存排序后的学生信息数据
int main()
{
long long studentID;
char studentName[10];
char studentSex[4];
int score[4];//定义要输入学生信息的变量；
char c;
int menu;//保存要进行的选项；
Open();
while (1)
{
system("pause");
Menu();
printf("请输入要进行的操作：");
scanf("%d", &menu);
switch (menu)
{
case 0:exit(0);
break;
case 1:
printf("请输入Y或y来添加数据\n");
scanf(" %c", &c);
while (c == 'y' || c == 'Y')
{
printf("请输入学生学号：");
scanf("%lld", &studentID);
printf("请输入学生姓名：");
scanf("%s", &studentName);
printf("请输入学生性别：");
scanf("%s", &studentSex);
int i = 0;
printf("请分别输入学生四门课的成绩：");
for (i = 0; i < 4; i++)
{
scanf("%d", &score[i]);
}
AppendNode(studentID, studentName, studentSex, score);
printf("请输入Y或y来添加数据\n");
scanf(" %c", &c);
}
DisplayNode(head);
break;
case 2:
FindID();
break;
case 3:
FindName();
break;
case 4:
DeleteNodeID();
break;
case 5:
DeleteNodeName();
case 6:
NumberSorting(1);
DeleteMemory(head1);
head1 = NULL;
break;
case 7:
NumberSorting(2);
DeleteMemory(head1);
head1 = NULL;
break;
default:
printf("输入有误！请重新输入");
}
}
Save();
DeleteMemory(head);
DeleteMemory(head1);
system("pause");
}
void AppendNode(long long studentID, char studentName[10], char studentSex[4], int score[4])
{
struct link *p = NULL, *pr = head;
p = (struct link *) malloc(sizeof(struct link));
if (p == NULL)
{
printf("申请内存失败");
return;
}
if (head == NULL)
{
head = p;
}
else {
while (pr->next != NULL)
{
pr = pr->next;
}
pr->next = p;
}
p->student.studentID = studentID;
strcpy(p->student.studentName, studentName);
strcpy(p->student.studentSex, studentSex);
p->student.score[0] = score[0];
p->student.score[1] = score[1];
p->student.score[2] = score[2];
p->student.score[3] = score[3];
p->next = NULL;
return;
}
void NumberSorting(int flag)
{
struct link *p = head;
struct link *p1 = head1;
int sum = 0;
if(p == NULL)
{
printf("没有数据，无法排序");
return;
}
while (p!=NULL)
{
switch (flag)
{
case 1:
InsertNode(p->student.studentID, p->student.studentName, p->student.studentSex, p->student.score);
break;
case 2 :
InsertNodeNumber(p->student.studentID, p->student.studentName, p->student.studentSex, p->student.score);
break;
default:
printf("程序异常，请重试!");
break;
}
p = p->next;
}
DisplayNode(head1);
}
void DisplayNode(struct link *head)
{
struct link *p = head;
if (p == NULL)
{
return;
}
printf("%lld", p->student.studentID);
printf("%10s", p->student.studentName);
printf("%5s", p->student.studentSex);
{
int i = 0;
for (i = 0; i < 4; i++)
{
printf("%4d", p->student.score[i]);
}
}
printf("\n");
DisplayNode(p->next);
}
void DeleteMemory(struct link *head)
{
struct link *p = head, *pr = NULL;
while (p != NULL)
{
pr = p;
p = p->next;
free(pr);
}

}
void InsertNodeNumber(long long studentID, char studentName[10], char studentSex[4], int score[4])
{
struct link *pr = head1, *p = head1, *temp = NULL;
p = (struct link *)malloc(sizeof(struct link));
if (p == NULL)
{
printf("内存申请失败");
return;
}
p->next = NULL;
p->student.studentID = studentID;
strcpy(p->student.studentName, studentName);
strcpy(p->student.studentSex, studentSex);
p->student.score[0] = score[0];
p->student.score[1] = score[1];
p->student.score[2] = score[2];
p->student.score[3] = score[3];
if (head1 == NULL)
{
head1 = p;
}
else
{
while (pr->student.studentID < studentID&&pr->next != NULL)
{
temp = pr;
pr = pr->next;
}
if (pr->student.studentID >= studentID)
{
if (pr == head1)
{
p->next = head1;
head1 = p;
}
else
{
pr = temp;
p->next = pr->next;
pr->next = p;
}
}
else
{
pr->next = p;
}
}
return;
}

void InsertNode(long long studentID, char studentName[10], char studentSex[4], int score[4])
{
struct link *pr = head1, *p = head1, *temp = NULL;
int sum, sum1;
p = (struct link *)malloc(sizeof(struct link));
if (p == NULL)
{
printf("内存申请失败");
return;
}
p->next = NULL;
p->student.studentID = studentID;
strcpy(p->student.studentName, studentName);
strcpy(p->student.studentSex, studentSex);
p->student.score[0] = score[0];
p->student.score[1] = score[1];
p->student.score[2] = score[2];
p->student.score[3] = score[3];
sum = p->student.score[0] + p->student.score[1] + p->student.score[2] + p->student.score[3];
if (head1 == NULL)
{
head1 = p;
}
else
{
sum1 = pr->student.score[0] + pr->student.score[1] + pr->student.score[2] + pr->student.score[3];
while (sum1 > sum&&pr->next != NULL)
{
temp = pr;
pr = pr->next;
sum1 = pr->student.score[0] + pr->student.score[1] + pr->student.score[2] + pr->student.score[3];
}
if (sum1 <= sum)
{
if (pr == head1)
{
p->next = head1;
head1 = p;
}
else
{
pr = temp;
p->next = pr->next;
pr->next = p;
}
}
else
{
pr->next = p;
}
}
return;
}

void DeleteNodeID()//输入学号删除
{
struct link *p = head, *pr = head;
long long studentID = 0;
if (head == NULL) {
printf("对不起，没有数据可以删除");
return;
}
printf("请输入你要删除的学生的学号");
scanf("%s", studentID);
while (studentID != p->student.studentID&&p->next != NULL)
{
pr = p;
p = p->next;
}
if (studentID == p->student.studentID)
{
if (p == head) {
head = p->next;
}
else
{
pr->next = p->next;
}
free(p);
}
else
{
printf("你要查找的这个数据未找到");
}
return;
}
void DeleteNodeName()//输入姓名删除
{
struct link *p = head, *pr = head;
char studentName[10] = "";
if (head == NULL) {
printf("对不起，没有数据可以删除");
return;
}
printf("请输入你要删除的学生的姓名:");
scanf("%s", studentName);
while (0!=strcmp(studentName,p->student.studentName)&&p->next != NULL)
{
pr = p;
p = p->next;
}
if (0==strcmp(studentName, p->student.studentName))
{
if (p == head) {
head = p->next;
}
else
{
pr->next = p->next;
}
free(p);
}
else
{
printf("你要查找的这个数据未找到");
}
return;
}
void Save()//保存链表中的数据
{
FILE *fp;
struct link *p = head;
if ((fp = fopen("demo.txt", "w")) == NULL)
{
printf("打开文件失败");
return;
}
while (p != NULL)
{
fprintf(fp, "%20lld%10s%5s%4d%4d%4d%4d", p->student.studentID, p->student.studentName, p->student.studentSex,
p->student.score[0],
p->student.score[1],
p->student.score[2],
p->student.score[3]);
p = p->next;
}
fclose(fp);
return;
}
void Open()//将文件中获得的数据写入到链表中
{
long long studentID;
char studentName[10];
char studentSex[4];
int score[4];
FILE *fp;
char c;
if ((fp = fopen("demo.txt", "r")) == NULL)
{
printf("文件打开失败");
return;
}
while ((c = fgetc(fp))!=EOF)
{
fscanf(fp, "%20lld", &studentID);
fscanf(fp, "%10s", studentName);
fscanf(fp, "%5s", studentSex);
fscanf(fp, "%4d", &score[0]);
fscanf(fp, "%4d", &score[1]);
fscanf(fp, "%4d", &score[2]);
fscanf(fp, "%4d", &score[3]);
AppendNode(studentID, studentName, studentSex, score);
}
fclose(fp);
}
void FindID()
{
struct link *p = head;
long long studentID=0;
if (head == NULL)
{
printf("没有数据查找");
return;
}
printf("请输入你要查找的学生的学号：");
scanf("%lld", &studentID);
while (studentID != p->student.studentID&&p->next != NULL)
{
p = p->next;
}
if (studentID == studentID)
{
printf("%lld", p->student.studentID);
printf("%10s", p->student.studentName);
printf("%5s", p->student.studentSex);
{
int i = 0;
for (i = 0; i < 4; i++)
{
printf("%4d", p->student.score[i]);
}
}
}
else{
printf("没有你要查找的数据");
}
return;
}
void FindName()
{
struct link *p = head;
char studentName[10] = "";
if (head == NULL)
{
printf("没有数据查找");
return;
}
printf("请输入你要查找的学生的姓名：");
scanf("%s", studentName);
while (0!=strcmp(studentName,p->student.studentName)&&p->next != NULL)
{
p = p->next;
}
if (0==strcmp(studentName,p->student.studentName))
{
printf("%lld", p->student.studentID);
printf("%10s", p->student.studentName);
printf("%5s", p->student.studentSex);
{
int i = 0;
for (i = 0; i < 4; i++)
{
printf("%4d", p->student.score[i]);
}
}
}
else{
printf("没有你要查找的数据");
}
return;
}

void Menu()
{
system("cls");//清平操作；
printf("\n\n\n\n\n");//输入回车，形成格式；
printf("\t\t|...........学生管理系统..............|\n");//
printf("\t\t|\t 0.退出。                     |\n");//“/t”水平制表，相当于一个tab键；
printf("\t\t|\t 1.添加学生成绩信息！         |\n");
printf("\t\t|\t 2.查找学生(按学号)信息！     |\n");
printf("\t\t|\t 3.查找学生(按姓名)信息！     |\n");
printf("\t\t|\t 4.删除学生成绩(按学号)信息！ |\n");
printf("\t\t|\t 5.删除学生成绩(按姓名)信息！ |\n");
printf("\t\t|\t 6.按总分排序！               |\n");
printf("\t\t|\t 7.按学号排序！               |\n");
printf("\t\t|...........学生管理系统..............|\n");//
}

如对程序有什么好的建议欢迎评论指教。。。。。。